linux-kernel - [PATCH 5/5] brd: Kill usage of page->index

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Date:   Wed, 13 Oct 2021 12:00:34 -0400
From:   Kent Overstreet <kent.overstreet@...il.com>
To:     linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        akpm@...ux-foundation.org, linux-raid@...r.kernel.org,
        linux-block@...r.kernel.org, axboe@...nel.dk
Cc:     Kent Overstreet <kent.overstreet@...il.com>,
        alexander.h.duyck@...ux.intel.com
Subject: [PATCH 5/5] brd: Kill usage of page->index

As part of the struct page cleanups underway, we want to remove as much
usage of page->mapping and page->index as possible, as frequently they
are known from context.

In the brd code, we're never actually reading from page->index except in
assertions, so references to it can be safely deleted.

Signed-off-by: Kent Overstreet <kent.overstreet@...il.com>
---
 drivers/block/brd.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 58ec167aa0..0a55aed832 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -72,8 +72,6 @@ static struct page *brd_lookup_page(struct brd_device *brd, sector_t sector)
 	page = radix_tree_lookup(&brd->brd_pages, idx);
 	rcu_read_unlock();
 
-	BUG_ON(page && page->index != idx);
-
 	return page;
 }
 
@@ -108,12 +106,10 @@ static struct page *brd_insert_page(struct brd_device *brd, sector_t sector)
 
 	spin_lock(&brd->brd_lock);
 	idx = sector >> PAGE_SECTORS_SHIFT;
-	page->index = idx;
 	if (radix_tree_insert(&brd->brd_pages, idx, page)) {
 		__free_page(page);
 		page = radix_tree_lookup(&brd->brd_pages, idx);
 		BUG_ON(!page);
-		BUG_ON(page->index != idx);
 	} else {
 		brd->brd_nr_pages++;
 	}
-- 
2.33.0